Sewing machine



O. R. HAAS SEWING MACHINE Oct. 7, 1941.

Original Filed Deo. 3l, 1936 2 Sheets-Sheet l O. R. HAAS SEWING MACHINE Oct. 7, 1941 2 sheets-sheet 2 Original Filed Dec.l5l, 1956 fnv/enfer' M@ /W www Patented Oct. 7, 1941 UNITED STTES PATENT OFFICE] j 2,257,950 't' 'V v SEWING MACHINE Y. Otto R. Haas, orth Beverly, Mass., assigner to United Shoe Machinery Corporation, Flemington, N. J., a corporation of ANew Jersey Original application December 31, 1936, Serial No. I 118,622. Divided and this application October 4, 1939, Serial N0.7297,912

sciaims. (ci, i12-ee)V li Y and the take-upmBy v so arranging' theftension The present invention relates to Wax thread shoe sewing machines, and more particularlyto improvements in a lockstitch machine in which each |stitch is set by a take-up acting against lthe resistance offered by a frictional tension wheel. An example of `a machine of this type is illustrated and described in U. S. Letters Patent of present inventor No. 2,148,197 of February 21, 1939, and in co-pending application Serial No. 118,622 filed December 31, 1936, of which application the present :application is a division.

In previous shoe sewing machines of this type, the take-up is arranged t0 oscillate about a shaft mounted as close as possible to the sewing point so that the length of thread which is acted upon by the take-up will be va minimum between the work Iand the tension wheel. The tension wheel ordinarily is located at one side of the plane through which the take-up oscillates andv the thread is carried from the tension wheel to the take-up from a series of angularly disposed pulleys. Not only do the pulleys over which the thread passes cause resistance to be imparted to the thread as the thread is drawn over them, but

also the length of thread required between the tension wheel and the take-up frequently is excessiveY so that the tendency of the thread to stretch and contract as the tension is applied and relieved vby movement of the take-up may result in undesirable irregularities in successive stitches of a seam. Y

The objects of the present invention are generally to provide a wax thread lockstitch shoe sewing machine which will operate smoothly .and accurately at speeds higher than'those heretofore successfully attained, with the same or a greater degree of uniformity between 'successive stitches in a seam and more particularly to provide an arrangement for controlling the tension ron the length of thread operated upon b-y the take-up of such a machine which will reduce the length of thread so operated upon and will cause less irregularity in .tension between successive operations of the take-up. Accordingly, one feature of the presen-t invention comprises a construction and arrangement in a lockstitch sewing machine having stitch-forming devices including a hook needle, a work support and a take-up, and a shaft for the take-up, of `a tension wheel having thread guiding means on its periphery arranged to rotate about an axis vat an angle to the take-up shaft with that portion of the periphery atvwhich the thread leaves the tension wheel located substantially in the plane through which the take-up oscillates between the axis of the take-up shaft wheel, no angularly disposed threadr 'guiding'pulleys yare required and yonly a singlev thread guiding pulley mounted to rotate in the same plane with the take-up is necessary, so that' the length' of thread between the tension and the work made as small as possible and little or no irregularity in the resistance offered by the pulley to the thread occurs. 1

A further feature of the invention relates to a cover for the take-up and tension wheel having angularly Adisposed portions respectivelyfor the take-up and tension wheel hinged to swing as a unitfaboutlan axis'parallel tothe take-up shaft so that Vthe take-up' and Vtension wheell will be exposed for threading or other adjustments by aA single 'swinging ,movement of the cover.

As hereinafter described, the cover cooperates with a guard portion of the machine framej and a further frictional tension device comprising mem'- bersl carried by the cover and guard actwith a yielding pressure on the thread between the take-'up 'and the work in order to facilitate the operation of the needle threading looper in laying the thread in the hook 0f the needle.

kWhile the present invention is herein illustrated vas being 4embodied in a lockstitch shoe sewing machine of the type referred to in certain of its features, the invention is advantageous Vwhen employed with other types of wax thread sewing machines such las chainstitch machines or machines having eye, pointed needles.

Other'features 0f the'invention relate to certain vnovel and improved constructions, combina-tionsand arrangements of parts hereinafter described in the following detailspeciiication, taken in connection with the accompanying drawings and more particularly pointed out in the appended claims. f

l Inthe drawings Figure 1 is a View in front elevation of a portion of the head of the machine jernbodying the features off ythe present invention;

Figure 2 is a View in vertical section taken along 'the line 2 2 of Figure 1, illustrating parts of the machine with the Work in operating position; and Figure 3 is a detail view partly in secj tion taken along the line 3 3 of Figure 2.

since its specic construction is immaterial. This mechanism is substantially the same as that disclosed in the present inventors prior U. S. Letters Patent No. 2,078,942 of May 3, 1937.

The stitch forming and work feeding devices of the machine are best illustrated in Figures 1 and 2, and include a curved hook needle I0, a curved awl I2, a rotating shuttle or loop taker I4, within a guideway 0f which is mounted a hollow circular thread case I6 containing a supply of locking thread, a looper I8, a thread hook or nger 20, a take-up 22 provided with a thread engaging member in the form of a roll 23, a presser-foot 24, and -a work support 26. The stitch forming devices of the machine are provided with means for drawing oif a measured amount of locking thread from the thread c-ase and a thread lock mounted on the thread case insures that only the amount of locking thread measured will be used in the formation and setting of each stitch. The work is fed continuously by alternate feeding movements of the presser-foot and work support as one unit and of the needle as another unit while engaging the work.

'I'he main take-up 22 is secured to an oscillating shaft 28 rotatable in bearings arranged in the machine frame parallel to the main sewing shaft. The take-up is oscillated through a uniform stroke during each sewing cycle to set each stitch and after a stitch setting strain is applied to the needle thread the take-up draws the required amount of thread from the tension wheel, indicated at 30. It is to be noted that the tension Wheel in the present machine is rotatably mounted on a stud arranged at right angles to the take-up shaft 28. Such an arrangement is not unusual where an attemptl is made to reduce the. length of thread acted upon by the take-up to a minimum. However, where such an arrangement has been used heretofore the tension wheel is located at vsome distance from the oscillating path of the take-up, and at least a pair of thread guiding pulleys in addition to the tension wheel is employed, one pulley being mounted at right anglesto the other to direct the thread from the plane of the tension wheel into the plane of the take-up path.

The arrangement of the tension wheel and take-up in the present machine is such that the periphery of the tension wheel, at the point where the thread leaves the wheel is substantially in the plane in which the take-up oscillates, and is located between the take-up shaft and the take-up roll. With such an arrangement only a single thread guiding pulley is required to direct the thread from the tension wheel to the take-up, the tension wheel itself acting to direct the thread from the plane of the wheel into the plane of the take-up path. From the tension wheel the thread passes over a single intermediate pulley 32 only (see Fig. 3) above the takeup shaft. This arrangement of the take-up and tension wheel also renders them easily accessible for threading.

The thread leaving the take-up extends in a substantially straight line to the looper I8 and is engaged between the loopery and the take-up by a frictional tension device comprising a plate 34 mounted in a stationary guard 35 for the takeup to press yieldingly against the thread and arranged with its thread engaging surface in the plane through which the take-up moves. 'I'he plate 34 is secured to a pin 36 slidably mounted for movement towards and from the thread and the ends of the plate are engaged by coil springs 38 mounted in recesses 40 in the guard. The springs 38 compress the plate 34 against the needle thread, gripping it frictionally between the plate and a cover 42 having a thread engaging surface 44 parallel to the opposing surface of the plate 34.

To release the frictional tension produced by the plate 34 on the needle thread as the threaded needle passes through the work, the pin 36 is slotted at its outer end and is engaged by the beveled end of a sliding rod 46 mounted in lugs formed on the guard 35. The other end of the rod 46acts against a cam 48 secured to the takeup shaft 28. To hold the rod against the cam, the rod carries near its beveled end, a coil spring `5l) compressed between one of the bearing lugs on the guard 35 and a collar 52 secured to the rod. To prevent the rod 46 from turning, one edge of the collar 52 is flattened to engage the side surface of the guard 35. The shape of the cam 48 is such that during the time when the take-up is at the lowermost part of its stroke, while the needle is being looped, the plate 34 is pressed against the thread and at other parts of the take-up stroke the plate is disengaged from the thread.

To shield the take-up and tension wheel, the cover 42 is formed with portions disposed at right angles to each other, one of which surrounds one. side of the take-up and the other of which encloses the tension wheel. At the side of the take-up opposite the cover 42 is the stationary guard 35 and the cover is hinged .to swing in a plane parallel with the oscillating path of movement of the .take-up about a pivot 54 parallel to the take-.up shaft so that the meeting edges of the guard and cover will slide along each other. They portion of the cover enclosing the tension wheel 30 is provided with an opening through which the adjusting nut for the tension wheel projects.

To prevent the cover 42 from displacing the needle thread when swinging the cover about the pin 54,A the driving and stopping mechanism of the machine is arranged to bring the machine to rest with the take-up 22 in a position near the lowermost part of its stroke. The beveled end of the rod 46 is then held against the pin 36 .and the plate 34 is retracted from the thread.

The nature and scope of the invention having been indicated, and a construction embodying the several features of the invention having been speciiicallydescribed, what is claimed is:

1. A lockstitch sewing machine having, in combination, stitch forming and work feeding devices including a hook needle, a work support, a presser-foot, a loop taker at one side of the work operated upon, a needle looper at theother side of the work, and a take-up, a thread engaging member on the take-up, a shaft about which the takeup oscillates and a tension wheel having thread guiding means about its periphery arranged to rotate about an axis at an angle to the take-up shaft with the portion of the periphery at which the thread leaves located between the axis of the take-up shaft and the thread engaging member and substantially in the plane in which the takeup oscillates.

2. A sewingmachine having, in combination, stitch forming devices including a work piercing needle and a take-up, a shaft about which the take-up oscillates, a tension wheel having thread guiding means about its periphery arranged to rotate about an axisat an angle to the take-up shaft, and a common cover having angularly disposed portions respectively for the take-up and the tension wheel hinged to swing as a unit about an axis parallel to the take-up shaft to expose the take-up and tension Wheel.

3. A sewing machine having, in combination, stitch forming devices including a hook needle, a needle looper, and a take-up, mechanism for oscillating the take-up, a frictional tension vdevice acting with a yielding pressure on the thread between the looper and the take-up and comprising members having opposed thread engaging surfaces, and connections actuated by the take-up oscillating mechanism for separating the thread engaging surfaces of the tension device during a portion of each sewing cycle.

4. A sewing machine having, in combination, stitch forming devices comprising a hook needle and a take-up, a hinged cover to enclose or permit easy access to certain of the stitch forming devices, a frictional tension device acting with a yielding pressure on the thread between the takeup and the point of operation of the needle and comprising opposed surfaces, one of which is carried by the cover and the other of which is actuated at the end of a seam to release the pressure on the thread.

5. A sewing machine having, in combination, stitch forming devices including a hook needle, a needle looper and a take-up, mechanism for oscillating the take-up, a stationary guard at one side of the take-up, a removable cover arranged when in position to surround the other side of the take-up, a frictional tension device acting with a yielding pressure on the thread between the takeup and the looper, and comprising members having thread engaging surfaces carried by -said guard and cover, respectively, and connections actuated by the take-up oscillating mechanism for separating the surfaces of the thread engaging members during a portion of each sewing cycle.

6. A sewing machine having, in combination, stitch forming devices including a hook needle, a needle looper and a take-up, mechanism for oscillating the take-up, a stationary member at one side of the take-up, a cover at the other side of the take-up hinged to swing in a plane parallel Y with the oscillating movement of the take-up, a frictional tension device acting with a yielding pressure on the thread between the take-up and the looper, and comprising a surface on the cover and a cooperating plate mounted on the stationary member having a thread engaging surface parallel to the direction in which the cover swings, and mechanism for moving the plate away from the surface on the cover at the end of a seam to prevent displacement of the thread along the tension surfaces when the cover swings into position.

OTTO R. HAAS. 

